Living in the heart of Edinburgh, Philippa Langley finds herself struggling after losing a coveted work promotion to a more attractive and less experienced colleague. Despite her efforts to confront her dismissive boss about the unfair decision, she is left feeling dejected. Dealing with her own challenges, including myalgic encephalomyelitis (often referred to as "ME"), her ex-husband, John Langley, reminds her of the importance of keeping her job to support their two teenage sons.
While attending a performance of Richard III, Philippa resonates deeply with the character, feeling that he has been profoundly misunderstood – labeled as a hunchback, usurper, and child murderer by history. She begins to experience vivid visions of Richard, leading her to join the local Richard III Society, where she finds a community that believes he has been unfairly vilified by the Tudor narrative.
As she grapples with her ME, Philippa gradually begins to detach from her work environment while managing her health with medication and engaging with her Richard apparition. Her extensive research reveals conflicting accounts about Richard's burial, with some claiming he was interred in the Leicester Greyfriars priory choir area, while others suggest his remains were discarded in the River Soar. An account from around 1600 mentions a shrine erected by Leicester's mayor, Robert Herrick, claiming, > "Here lies the body of Richard III, sometime king of England."
Philippa decides to attend a lecture in Leicester about Richard, concealing her true intentions from John. There, she encounters Dr. Ashdown-Hill, who is investigating the genealogical lineage of Richard III’s family and suggests searching for Richard's remains in Leicester's open spaces, as many have historically avoided constructing over ancient abbeys. During an exploration of Leicester, Philippa becomes convinced that an "R" painted in a parking lot marks Richard's burial site and later confesses her plans to John.
Determined, Philippa reaches out to Richard Buckley, an archaeologist at the University of Leicester. Initial skepticism accompanies his response; however, when funding for his project is cut, he revisits Philippa's idea. He discovers a historical map highlighting Robert Herrick's property, indicating a potential connection to the public shrine. Together, they superimpose the old map onto a contemporary one and deduce that the shrine corresponds to the area of Philippa's "R".
With renewed vigor, Philippa and Buckley approach the Leicester City Council for support. Even though university advisor Richard Taylor expresses concerns about the risks tied to Philippa's amateur estimation, the Council grants approval for excavation to boost local interest. Unfortunately, when ground-penetrating radar reveals no significant finds, funding dwindles. Undeterred, Philippa turns to the Richard III Society for crowd-funding, which successfully provides global financial backing for three trenches.
On the first day of the dig, Buckley informs Philippa that while the dig certificate is signed, her name has been conspicuously omitted. Despite this, she insists on focusing the excavation at the designated "R" location, where they quickly uncover human remains. Buckley initially speculates it could be an extramural graveyard associated with monks. Tensions rise as Philippa confronts Taylor for commandeering credit for the project. As they begin to uncover the skeleton, the osteologist identifies it as that of Richard III, a man with a pronounced spinal curvature and evidence of a fatal skull injury.
Following this breakthrough, leaders from the University of Leicester rush to assume control of the excavation efforts, re-engaging Buckley. In February 2013, Taylor triumphantly presents their findings at a press conference—though Philippa finds herself sidelined along with much of her contribution. In a touch of poetic justice, Buckley is later awarded an honorary doctorate for the undertaking.
In a poignant farewell, Richard appears to Philippa one last time at Bosworth Field, expressing his gratitude before vanishing. The film concludes with his funeral, fit for a king, taking place in Leicester Cathedral, while the closing credits reveal that the royal family's website has officially acknowledged Richard as the rightful King of England from 1483 to 1485, correcting historical misconceptions. In recognition of her relentless pursuit for the truth, Philippa is honored with an MBE for her groundbreaking work.
